AutoCAD® Civil 3D® 2012 Essentials: Autodesk® Official Training Guide: Essential

Using Breaklines to Improve Surface Accuracy

The TIN algorithm creates surfaces by drawing 3D lines between points that are closest to each other. In certain instances, this is not the most accurate way to model the surface and the TIN lines must be forced into a specific arrangement. This arrangement typically coincides with a linear feature such as a curb, top of an embankment, or wall. This forced alignment of TIN lines along a linear feature is best handled with a breakline. In Figure 4.6, the blue lines represent the edges of a channel and the TIN lines are shown in red. In the image on the left, the blue lines have not been added to the ...